Abstract: What is network? It is a theoretical and practical issue that needs to be talked. Different understandings of the network will lead to different network behaviors and different network realities. Understanding network can proceed from the characteristics of human network interaction, to prove the reality of the network, to understand the nature of the network information, to recognize the intelligent creation function of network, and to feel the spiritual attributes of the network. Understanding network needs to confirm the realistic of network, and understand the status and role of network in human’s information activities, intelligent creative activities, and Mental activities.